I don't work labor anymore but when I did it was all about water, water, water. Light clothes help. I ended up with one of those water jugs in a back pack with a straw you can drink out of. Worked well. Fill the pack with ice, then top off with water and you get really cold water for several hours. I still use it on rides sometimes, it's nice because my bike runs really hot and when it's 90-100 deg F + outside and you have jeans, boots, a jacket, gloves, and a helmet on it feels even hotter.